I'm not religious so I don't really support it, I'm just trying to play devil's advocate. It seems to me that there is a significant difference between "my religious organization was founded with the express purpose of supporting slavery, at a time and place when slavery was the most important political issue in the country" and "homosexuality is just one of a long list of things that are banned, but is not called out in any sort of special way"
What's actually in scripture has very little to do with the religious beliefs many profess.